1. Field of the Invention
This invention relates generally to telecommunications, and more particularly, to wireless communications.
2. Description of the Related Art
Use of mobile services is on the increase. Until recently, however, most wireless devices have been used only for voice transmissions, but many new wireless devices deliver both voice and data communications. While more and more data is shifted between networks, the users of these wireless devices expect a higher service quality without delay of applications and packet loss, for example, in Internet based wireless multimedia communications and services. To keep up with such a demand of bandwidth for wireless communications, network providers are increasingly deploying wireless mobile communication systems that carry voice and data simultaneously to a single user.
For example, one such technique that may multiplex voice and data referred to as High Speed Downlink Packet Access (HSDPA) is based on a Wideband Code Division Multiple Access (WCDMA) specification for Universal Mobile Telecommunications Systems (UMTS). This technique enables user peak data rates and a quality of service for downlink packet data services. A HSDPA transmission may allocate up to twenty fixed power codes per carrier. The HSDPA transmission may set a data rate for a wireless communication depending on the results of channel quality estimation. The HSDPA transmission may assign codes to a user on a 2 ms frame rate on a first come first served basis and as a function of the amount of data to be transmitted. However, this technique may result in a significantly large step changes in transmit power of a transmitter at a 2 ms frame rate intervals.
Moreover, the HSDPA transmission may add significantly to a peak-to-average power ratio (PAR) of a transmitted signal because some user equipments (UEs) are unable to process adjacent data frames. For instance, if such a UE receives a large data file, the transmitter sending the data may experience a 8 dB step in transmit power on a 2 ms frame rate. The unclipped PAR increases from approximately 10 dB for a voice transmission, to about 11.6 dB. This unclipped PAR increase is likely to have a substantial impact on peak limiting algorithms, power amplifiers and pre distortion units of a transceiver, such as a base transceiver station (BTS) at a base station, i.e., a Node-B in a wireless mobile telecommunication system.
The present invention is directed to overcoming, or at least reducing, the effects of, one or more of the problems set forth above.